In many different fields of lighting technology (e.g. industry, offices, schools/universities, and hospitals), light management, or lighting control, has become increasingly important. It is increasingly frequent that lighting is controlled, or switched on and off, depending on various factors. Thus, in order to save energy, a daylight control, or a control based on presence notification or absence notification is used. A daylight control can also serve to maintain a more or less uniform light level in a building or a room over the course of the day.
Another field in which light management, or lighting control, has become increasingly important is assessing the effect of the light on the well-being and productivity of humans located in the lighted region of such a lighting. It is already known that the type of light emission has an effect on human biorhythms, wherein it is generally assumed e.g., that light having a higher blue content has a stimulating effect, while in contrast, lower color temperatures are more calming. Various advantages can be obtained in different applications by influencing humans through the type of light emission. It is thus conceivable: e.g., in industry, for the light to have a stimulating effect, resulting in fewer absences and a higher productivity by the employees; in offices, a greater level of physical comfort resulting in higher productivity can be obtained; in schools/universities, a stimulating effect resulting in an improved learning behavior can be obtained; and in hospitals, this can be used in supporting the healing process, and to produce a calming effect.
Numerous studies have already been conducted regarding the effects of light on human well-being and productivity, the validity of which is questionable insofar as only a relatively small number of test subjects have been studied, because such studies are relatively complicated. is the studies are complicated because, among other things, a sampling of people having different demographic backgrounds are required to come into a laboratory, where their physiological reactions are measured. Because of this complexity, such studies are carried out with a limited number of people (a maximum of a few hundred people). Furthermore, physiological reactions such as stress, pulse rate, etc. are affected by a number of factors, e.g. the current physical state of being. Due to the low number of participants, it has hardly been possible in the studies so far to form clusters according to age, sex, etc.
The validity of such studies is, accordingly, fairly low, and only very little useful information regarding optimal lighting control has been obtained from the studies.
Moreover, it should also be noted that dimming and color temperature sequences are permanently stored in present day systems, and cannot be adapted, e.g. to site-specific conditions. The system also receives no feedback as to whether such sequences have a positive effect on the people in question.
On the whole, the previous studies have provided hardly any reasonably usable information on how lighting control has a positive effect on the majority of people, in terms of well-being and productivity.